Printing telegraph



Nov. 1, 193.8. 1.. H. JAMES ET AL.

PRINTING TELEGRAPH v Filed April 6, 1938 5 Sheets-Sheet 1 m w A? 5.

L. H.-JAMES ET AL Nov. 1, 1938.

PRINTING TELEGRAPH Filed April 6, 1938 5 Sheets-Sheet 2 NOV. 1, 1938. JAMES ET L 2,135,398

PRINTING TELEGRAPH Filed April 6, 1958 5 sheets-sheets MOPB Imnenfor immiomgu/vm ws mmgm% d ttomegs 1.938- L. H. JAMES ET AL. 2,135,398

PRINTING TELEGRAPH Filed April 6, 1938 5 Sheets-Shed 4 A1 :Ho/Qw 903m Dom Spence/09mm dnomegs CC MROJ 15B L Nov. 1, 1938. H, A E AL 2,135,398

PRINTING TELEGRAPH Filed April 6, 1938 5 Sheets-Sheet 5 C(ttornegs Patented Nov. 1, 19 38 UNITED STATES z.1s5,s9s ram'rmo TELEGRAPH.

Louis Horn James and Don Spencer James, Los Angeles, Calif.

Application April 6, 1938, Serial No. 200,540

30 Claims. (Cl. 178-52) This invention relates to printing telegraph systems, and in particular to arrangements'for repeating or relaying signals from one multiplex system to another or from a multiplex system 5 to a start-stop system and vice versa, and without the necessity for manual operation in the relaying process.

In existing printing telegraph systems where two independent multiplex systems terminate in a common station, and it is desired to relay a message from one system onto the other, it is now common practice to receive the message on the incoming system, perforate a tape according to the received message, and then run the tape through a tape transmitter on the outgoing system. This necessitates considerable delay in formed of four impulses of one polarity and a flfth, impulse of opposite polarity. The invention is not limited to systems employing this particular type of idle signal but may be adapted for idle signals of a diii'erent combination of positive and negative impulses. The start-stop systems involved in the present invention are of the type employing a normally closed transmission circuit and in which thecircuit is opened to start the receiving printer in operation, and there after the. circuit is closed for marking impulses and opened for spacing impulses.-

An object of the invention is to devise an arrangement whereby the signalsreceived on a multiplex system will directly control the circuit of an outgoing start-stop system.

, .A further object is to provide relaying means by which signals received on an incoming multiplex system may directly control the transmitting apparatus on an outgoing multiplex system and in which the incoming signal is re-iormed or regenerated inthe'relaying process.

Another object is to devise arrangements for directly relaying the message from a start-stop circuit onto an outgoing multiplex system.

Still another object is to devise arrangements for maintaining two independent multiplex sys- Items in synchronous operationand to secure combinations consists of five-unit impulses vary-' ing in polarity according tothe character being transmitted, and in which the idle signals are x I 1 stop'system and vice versa;

proper phasing adjustment between. the distributors onthe two'systems.

A further object is to provide monitor printers at the multiplex relay or central station whereby all messages transmitted out of the station over a multiplex system may be supervised and whereby copies of all messages relayed over the multiplex system or transmitted therefrom may be retained at the station.

A further object is to devise an arrangement whereby the signals received on a multiplex system will operate the local printer and directly control the circuits of an outgoing start-stop system and an outgoing multiplex system simultaneously.

It is a further object of the present invention to carry out the foregoing objects by simple changes or additions to existing apparatus now in common use in multiplex systems of the Morkrum type and in start-stop systems now in common use.-

Fig. l of the drawings shows the relation-between the iour sheets containing Figs. 2, 3, 4 and 5 which constitutea schematic circuit diagram of a system according to the invention for repeating .from one multiplex system to another or for repeating from one multiplex system to a start- Fig. 2 is a circuit diagram showing part of the apparatus located at a central oiiice and associated with a west multiplex system WM;

Fig. 3 shows the remaining apparatus located at the central station and associated with the system WM, and also illustrating a start-stop receiver SSR located at a distant substation;

Fig. 4 shows part of the apparatus located at the central station and associated with an east multiplex system terminating in the station;

Fig; 5 shows the remaining apparatus located at the central station and associated with the east multiplex system EM, and also illustrating a start-stop transmitter SSTlocated at a distant sub-station Fig. 6 is a schematic circuit-diagram illusterminates in the central station and operates receiving relay WR which in turn controls the multiplex printer relay PR. which controls circuits of the printer magnets in two multiplex printers represented in the dotted rectangles MPA and MPB. The circuits of the printer magnets of. printer MFA in the A channel are controlled by the distributor switches operated by multiplex distributor cams Al to A5 inclusive, and the circuits for the selecting magnets of printer MPB in the B channel are controlled by switches operated by distributor cams BI to B5 inclusive. The sixth pulse for operating each of the printers MPA and MPB is supplied by switches operated by distributor cam Cl driven synchronously with the cams Al to A5 and BI to B5 inclusive. The multiplex distributor is also provided with corrector cam CR for maintaining proper phase relation for this distributor and since corrector apparatus is well known, it is not being shown.

The apparatus illustrated in Fig. 2 is standard multiplex apparatus now in common use in printing telegraph systems, except that normally the sixth impulse for the two printers is supplied by switches controlled by separate cams, but in order to reduce the number of cams, it is preferred to use the Cl cam for supplying the sixth pulse to both printers.

Referring to Fig. 3, the multiplex distributor associated with the west multiplex WM is provided with four specially formed cams C2, C3, C4 and C5. These cams replace standard cams for the purpose of the present invention. It will be understood that in the standard multiplex apparatus of the prior art a cam normally in the position of C2 is employed for supplying the sixth impulse to printer MPB.

The present invention involves a polarized repeater relay 3 shown in Fig. 3 controlled by the receiving relay WR of. Fig. 2 through the connection 3a, and the tongue of relay 3 operates between fixed contacts which are connected respectively to fixed contacts of a switch 4 controlled by cam C3, and the tongue of switch 4 controls the operating circuit of a start-stop repeater relay 5. Relay 5 is provided with biasing winding 50 which normally maintains the relay tongue on the left contact or in the spacing position but is operated to the marking position when positive battery is supplied to the relay winding by relay 3 through the cam switch 4. Cam C4 operates a switch I for controlling the start-stop channel A, and the cam C5 operates the switch 8 for controlling the start-stop channel B. One stationary contact of switch I is connected to positive battery througha normally closed start switch CZA controlled by cam C2, and the other stationary contact of switch I is connected to the stationary contact of relay 5.

In a like manner, one stationary contact of switch 8 is connected to positive battery through 9. normally closed start switch 023 controlled by cam C2 and the other stationary contact of switch 8 is connected to the stationary contact of relay 5. It will be understood that switches CZA and C213 associated with cam C2 provide the start impulse for the start-stop apparatus on the two channels. The rectangle SSR represents a start-stop receiver connected to channel A by jack J I, and it will be understood that this receiver may be located at a distant sub-station. The jack *JZ is provided so that a message received on the multiplex channel B may be relayed to a startstop receiver at a distant sub-station.

The cam C3 is so positioned with respect to h l is operative.

printer cams on the multiplex receiving distributor that it operates a switch 4 from one position to the opposite position between the fourth and fifth pulses of the multiplex signal combination, and this occurs for both channels. In Fig. 3, the arrows associated with the letter A indicate the period during which the channel A is operative and the arrows associated with the letter B indicate the period when the channel B The object in providing cam C3 to operate switch 4 in the manner described is to convert the received multiplex signal into a signal for operation of the start-stop signalling circuit in which the circuit is to be closed for marking impulses and is to be open for spacing impulses. Cam C3 operates switch 4 from one position to the other between signal units in which marking impulses are of opposite polarity.

Relayina signals from multiplex to start-stop receiver momentary opening of the circuit for the start impulse, cam C2 has no further control of the circuit due to the operation of switch 1, but the start-stop circuit is controlled in accordance with the operation of the relay 5 which in turn is controlled hy cam switch 4 and by polarized relay 3.

Assume that idle signals are being transmitted from multiplex line WM, then the signal impulses on channel A will consist of four negative impulses followed by a fifth positive impulse, all five impulses being spacing impulses. During the time that these five signal impulses are transmitted, cam- C3 rotates through the angle A in Fig. 3, and for the four negative impulses. the switch 4 is connected as shown in Fig. 3, but since the tongue of relay 5 is held against the right-hand contact by the negative impulses, relay 5 remains in the spacing position and the start-stop line remains open. Just prior to receipt of the fifth or positive impulse, cam CI shifts the tongue of switch 4 to the right-hand contact and prevents operation of relay 5 when the tongue of relay 3 is operated to the left-hand contact by the positive impulse. Thus only spacing impulses will be transmitted to the start-stop line when idle signals are received over the multiplex system. Also all negative impulses received over the multiplex system during the first four impulses of a signal combination, and a positive fifth impulse, will be repeated to the start-stop line for channel A as spacing impulses, and all positive impulses received over the multiplex channel A during the first four impulses of a combination, and a. negative fifth impulse, will be repeated to the start-stop line as marking impulses. It should be noted that the starting of the start-stop receiver is controlled from the multiplex distributor by means of cam switches 02A and 02B controlledby cam C2. The startstop distributor for the receiver SSR is arranged to operate at such speed that it makes a complete cycle of operation during one-half revolution of the multiplex distributor, and during the time that channel A is operating, the start-stop line for channel B is closed through cam switches 02B and 8. In a like manner when start-stop channel B is operating, the line for channel A remains closed through cam switches CZA and I. If desired, cam switches I and 8 may be arranged on opposite sides of a single cam and operated thereby.

Relaying signals from one multiplex system to another multiplex system The present invention involves arrangements for repeating signals received on one multiplex system onto another multiplex system and in which the standard multiplex tape transmitters and distributors on the outgoing system are utilized for re-forming or renegerating the signal impulses as they pass from one system to the other.

Figs. 4 and 5 show the transmitting apparatus associated with'an east multiplex system EM and located in the same central station with the re.- ceiving apparatus shown in Figs. 2 and '3 and associated with the west multiplex system WM. It will be understood that the drawings illustrate apparatus for transmission over two multiplex channels from the west system to the east system only, but duplicate apparatus (not shown) is provided for transmission in the opposite direction.

For the purpose of controlling the transmitter on the east multiplex system in accordance with signals received on a channel A of the west mul tiplex system, the energizing circuit of relay 5 is extended through jack J3, throughpord circuit apparatus on the east system EM, as will be described in greater detail below. In a like manner,

signals received over channel B of the west system may be relayed to the east system by extending the circuit of relay 5 to control the operation of relay 63 (Fig. 5) by means of a cord circuit joining jacks J4 and J6.

Referring to Fig. 4, the two tape transmitters of the two multiplex channels on the east system are shown at TA and TB respectively. These transmitters are of standard construction, and it will be understood that normally when the transmitters are idle the tongues of the transmitters will lie against the left-hand contacts. The impulsetransmitting circuits for transmitter TA arecontrolled by the cam switches operated by cams AI to A5 inclusive on the multiplex distributor and the impulse transmitting circuits of transmitter T3 are controlled by the cam switches operated by cams BI to 3'5 on the multiplex distributor. The sixth impulse for transmitter TA is supplied by cam switch 9a operated by distributor cam C6 while the sixth impulse for transmitter TB is supplied by cam switch 9b operated from the same cam C6. In thestandard equipment, the switch 91) is operated by a sepbered cams on the transmitting distributors are connected to the split or midpoint of the ammeter on the multiplexsystem EM through the cam switch I6 and the distributor contacts associated with the even numbered cams on the multiplex distributor are connected to the ammeter split.

through cam switch II.

In the standard multiplex transmitters, the.

stationary contact leads Lb and La are normally permanently connected to plus and minus battery, but forthe purpose of this invention, the contact leads La and Lb are connected to the tongues of two pole changing relays I0 and II respectively, the tongues of these two relays operating between fixed contacts of plus andminus battery, and operation of the relays from one position to the other effects reversal of the polarity of the battery applied to the leads. La and Lb.

Relays I0 and II are polarized relays and are locked in the operated position bya polarized relay I2 which closes a. circuit to energize holding coils Illa, Ila and I2a on relays III, II and I2, respectively. The common energizingcircuit for relays Ill I I and I2 is controlled by input relay 6A and the circuit extends from the tongue of relay 6A through cam switch I3A controlled by cam C1 and through either cam switch I4 or ity of falseoperation of the pole changers III and II in case of slight de-phasing of the signal with respect to the distributor. Cams ACI and AC2 form a part of the regular multiplex transmitting distributor, and in order to utilize the existing cam surface on these cams the plunger shoes Ila and I5a have an extended contact area of the shape shown in Fig. 5, so that the plungers will remain in the cam indentations only a short time. The trailing edge of the face of the plunger shoes is cut away to such position that the.

plunger operates at a .time to compensate for the delay or lag in operation of pole changers ID and II and locking relay I2. This insures identical phasing of operation between pole chang-v ing relays I0 and II and-the AC distributor contacts I6 and I1 controlled by cams ACI and AC2.

Relays 6A and GB for controlling the energizing circuit ofzrelay's II), II and I2 are provided with biasing windings 6a and 6b respectively,

which normally maintain the tongues of these relayson the left-hand contact or in the spacing position and normally apply positive battery to the operating circuit of relays III, II and I2. Normally, relay I0 applies negative battery to transmitter lead La and relay II supplies positive battery to transmitter lead Lb.

Assume that it is desired to relay signals arriving on channel A of the west system onto the corresponding channel in the east system, the energizing circuit of relay 5 is extended to operate relay 6A over the cord circuit CC as shown in Figs. 3 and 5'.

Assume for the time being that idle signals are being received, over the west system consisting of four negative impulses followed by a fifth positive impulse. The first four negative impulses cause relay 3 to operate to the right-hand contact, and since cam switch 4 is openduring the first four impulses on channel A, the energizing circuit of relay 6A extending through the winding of relay remains open, and the tongue of relay 6A continues to apply positive battery to the windings of relays III, I l and 12 through contact ISA and alternately operating switches l4 and I5. Since the relays i0 and H remain in the left-hand position during the first four impulses on channel A, relay l0 applies negative battery to the first four contacts on transmitter TA and relay ll applies positive battery to the fifth contact on transmitter TA. Accordingly, the first four negative impulses received on the west system will be transmitted as negative impulses on the east system. The fifth positive impulse received on the west system operates relay 3 to the left-hand position, but just prior to its operation, switch 4 is operated to the opposite position by cam C3 and the energizing circuit to relay 6A remains open and relays i0, II and I! remain in their'locked position. Accordingly, the fifth impulse transmitted over the east system is determined by the polarity of transmitter lead Lb which under this condition is positive.

Assume now that a positive impulse is received over the west system during the first iour impulses on channel A, relay 3 will be operated to the left and thereby apply positive battery to the energizing circuit of relay 6A through the winding of relay 5, and relay 6A will apply negative battery to the common operating circuit of relays Hl, H and i2 through switch I3A met through one of the switches H or IE. This causes operation of all three relays to the right-hand position and relay l2 closes a holding circuit for all three relays to maintain the relays in operated position after the momentary closing of the switch I4 or ii. Operation of relay ill to the right reverses the polarity of the battery applied to the first four contacts of transmitter TA, and this results in the transmission of a positive or marking impulse to the east system in response to the marking impulse received on the west system.

By the use of pole changing relays l0 and H controlled by the locking relay l2, and by controlling all three relays by the alternate momentary closing of switches l4 and II, all signal 1mpulses which are relayed from thewest system to the east system are completely reformed or regenerated at the central station in theprocess of being relayed to the east system.

In case it is desired to relay signals from the west system to the east system on both channels. a cord circuit similar to circuit CC will-be employed to connect jack J4 with jack J6 so that, relay 6B is energized in a circuit in series with relays 5 and 6A. Under this condition, signals received over channel B will be relayed through the apparatus shown in Figs. 4 and 5 during the time that distributor contact I313 is in closed position.

It will be understood that transmitters TA and TB may be employed in the ordinary manner for transmitting multiplex signals from the central station over the east -system to a distant multiplex station, and this may be done without any change in the arrangement shown. For example, when channel A of the east multiplex system isidle, signals may be transmitted over this channel from the central station by passing perforated tapethrough the transmitter TA .in the usual manner. It will be understood that normally when no signals are being relayed through the transmitter equipment, the relay, 6A remains on the left-hand contact and, applies positive stop receiver.

battery to relays III, II and I2 so that these relays remain inilocked position on the left contacts during transmission of multiplex signals through transmitter TA. Obviously, both transmitters TA and TB may be operated simultaneously, if desired.

Relaying signals from a start-stop system to a multiplex, system The present invention also provides arrangements at a' multiplex terminal station or central station for relaying onto the multiplex system signals received at the station over -a start-stop a distributor or commutator provided with a stop contact Sp which is normally closed when the transmitter is at rest, and a normally open start contact St followed by five contacts for transmitting the signal impulses. The transmitting apparatus also includes a tape transmitter Tc having five tape control tongues which normally lie against the left-hand stationary contacts and are operated to the right-hand contacts according to the signal perforated in the tape. Thepresent invention contemplates the use of the start-stop transmitting apparatus for transmitting signals from a sub-station to a startstop receiver at the central multiplex station, and also for the purpose of transmitting signals from the substation to the central station to be relayed onto a multiplex channel. In order to adapt the start-stop transmittingapparatus for transmitting signals to the central station to. be relayed over the multiplex system, certain changes in the transmitting apparatus must be made in order to avoid the transmission of continuous marking signals to the multiplex channel when the start-stop transmitter at the sub-station is idle. The necessary changes for converting the start-stop transmitting apparatus from a condition for straight start-stop operation to a condition for relaying signals onto a multiplex system are secured by means of a switch II which when moved in the direction of the arrow 8 conditions the apparatus for start-stop transmission in the usual manner to a start-stop receiver at the central station, and when moved in the direction of the arrow M, conditions the apparatus for trans mitting signals to the central station to be relayed onto the multiplex system.

For a straight start-stop transmission from the sub-station to' the central station, switch ll is moved in the direction 8, and contact 080. opens and leaves the distributor contact St disconnected so. that the starting impulse is transmitted over the line. Contact lib supplies positive battery to the starting magnet SM through the operatorswitch 08. Contact lac supplies positive battery to the right-hand stationary contacts of the transmitter Tc. It will be observed that with switch I! in the upper position, the connections of the transmitting apparatus are according to standard connections for a startstop transmitter, and by feeding a perforated tape through the transmitter Tc, start-stop signals will be transmitted to the central oflice where they will be received on a standard start- A standard start-stop receiver (not shown). is provided at the sub-station for receiving messages from the central station.

For transmission from the start-stop sub-station to the multiplex channel, the switch I8 is moved to the lower position where contact l8a connects the starting contact St to the stop contact Sp, and contact lBb moves to open position so that the circuit to the start magnet SM is I the start-stop channel B through jack 20B,

T to

or to the multiplex channel A through jack 20A, depending upon which channel is available. Biasing coils 6a and 61) on relays 6A and 6B are normally supplied with positive current through jack contacts 260. and 20b to normally maintain the tongues of relays 6A and 6B on the positive terminal, but operation of jack contacts 280. and 20b by a plug inserted in these jacks reverses the polarity of the battery applied to biasing windings do and 6b whereby the tongues of relays 6A and EB are biased to the negative contact. The circuits completed from the start-stop lines to relays A and 613 include series resistances 2| A and MB which are selected with resistance values suificiently large to prevent operation ofrelay is at the start-stop station by current supplied from positive battery at the sub-station through the operating winding of relay l9, but the current is sufiiciently large to hold-the tongues of relays 6A and. 6B against their positive contacts in opposition to the action of biasing coils 6a and 6b. Upon short-circuiting of these resistances, the current increases to a value sufficient to operate relay l9 and thereby energize start magnet SMI to start the start-stop transmitter. For the purpose of transmitting the start impulses at the proper time on the two channels, a pair of contacts 22A and 22B are associated with appropriate cams on the multiplex transmitting distributor, the two contacts being operated 180 apart and being adjustable in position about the axes of the cams to secure proper phasing of the operation of the startstop transmitter with the multiplex distributor.

When the start-stop line is connected to one of the multiplex channels as shown in the case of the plug insert in jack 203, the contact 2% on the jack is operated to change the polarity on the biasing winding 8?), so that relay 6B is biased towards the negative contact. When the startstop transmitteris operated for transmission over the multiplex channel, the signal impulses transmitted by transmitter Tc vary from that of normal operation in that the ,circuit is opened for marking impulses and 'closed for spacing impulses. Thus, if the transmitter To opens the start-stop circuitduring any one of the first tour impulses of a signal combination, relay 6B is held against its negative terminal by biasing winding lib, and this relay impressed negative battery on relays Ill, Ii and i2 through distribu- If start-stop transmitter Tc should close the circuit during any of the first four impulses, relay 63 will be operated to its positive contact and thereby operate relays I0 and II to the left. Relay l I impresses positive battery on the first four contacts of multiplex transmitter TB and a positive spacing impulse will be transmitted over channel B. If the start-stop transmitter circuit is open on the fifth impulse, relay BB remains on the negative contact and relay l0 supplies positive battery to the fifth contact of multiplex transmitter TB, and a marking impulse is transmitted to the east system. In case the start-stop line is closed on the fifth impulse, relay 6B operates to the positive terminal and causes relay W to operate to the. left and impress negative battery on the fifth contact of multiplex transmitter TB and thereby transmit a negative or spacing impulse to the east system.

In case the operator at the sub-station opens the switch OS the start-stop transmitter at the sub-station will not be operated by the start impulses from the central station. Also, since the start impulses do'not afiect the. operation of relay 6B, the tongue of this relay is held on the positive or spacing contact when the start-stop transmitter is idle. This prevents the transmission of continuous marking signals over the multiplex channel when the start-stop transmitter is idle. I

Synchronous operation and phasing adjustment of "two multiplex systems multiplex system and the parts shown to the right i are associated with the transmitting distributor on the east multiplex system. The motor for driving the receiving distributor on the west system' is shown at 23, and the speed of this motor is controlled by fork 23a operating. through transformer 23b, stabilizing lamp 231; and the A. 0. rings 23d. The speed of operation of the fork 23a is controlled in a well understood manner by the corrector circuit and the automatic speed control rheostat 23c which supplies current to the adjusting magnets 23f associated with fork. 23a through the usual phasing switch 23g. The apparatus described above is standard.

The motor for driving the transmitting distributor on the outgoing or east multiplex channel is shown at 24 and is controlled by fork 24a operating through transformer 241), through stabilizing lamp 240 and A. C.'rings Md. The fork 24a is driven from the fork 23a by a connection 23-24 added accordingto the present invention. This invention also adds adjusting magnets 24c for controlling the period of operation of the fork 24a, and the current supplied to these magnets is controlled by the phasing switch 24f arranged to be operated simultaneously with phasing switch 23g. A resistance 24g is provided to limit the current in the adjusting magnets Me in the normal running position of the switch 24 An additional fork 25 having a speed slightly higher than fork 24a is provided for controlling the speed of'the motor 24 during the phasing operation through transformer 25a. and through the back contacts on phasing relay 26.

A phasing contact 21 is added to the receiving distributor on the west system and is operated by one of the cams of this distributor. This contact supplies positive battery through a circuit including similar phasing contact 28 associated with a corresponding cam on the transmitting distributor for the east multiplex channel, the circuit continuing to the operating winding of relay 29 which is provided with a biasing coil 29a to maintain its tongue in open position. The added phasing contact 28 on the regular multiplex transmitting distributor is arranged so that it may be adjusted about the axis of the distributor to secure the desired adjustment in phase relation. Relay 29 controls the circuit to relay 26 through a phasing switch 30. Relay 26 is provided with a contact 2611 which completes a looking circuit when energized, the locking circuit being controlled by the phasing switch 30.

The phasing operation is as follows:

It will be assumed that motor 24 is being controlled from the fork 24a and that the transmitting distributor on the east system is out of phase with the receiving distributor on the west system. Under this condition relay 26 is in locked position and fork 24a controls motor 24 through relay contacts 262) and 260. In order to properly phase the transmitting distributor with respect to the receiving distributor, the switch 30 is momentarily depressed, thereby de-energizing relay 26 and connecting fork 25 to control the motor 24 instead of the fork 24a. This operates to increase the speed of the motor 25 and therefore speed up the transmitting distributor with respect to the receiving distributor. As soon as the two distributors attain the same phase relation, contacts 21 and 28 are closed at the same instant and the energizing circuit to relay 29 is closed, thus causing operation of this relay to complete the circuit to relay 25 which operates and disconnects fork 25 from the motor 24 and reconnects fork 24a to the motor. From this point the transmitting distributor will operate synchronously and inphase with the receiving distributor. Neon lamp 3| is connected across the energizing circuit to relay 2! for the purpose of giving a visual indication of the proper phasing condition of the two distributors.

If for any reason it becomes necessary to adjust the phase of the receiving distributor with respect to its transmitting distributor on the same channel and in the same system, the phasing switch 239 is operated for this purpose, and by interlocking this switch with the phasing switch 24 controlling the adjusting magnets on the fork 24, a corresponding adjustment in the phase of the outgoing transmitting distributor is ob tained without changing the proper phasing between the incomingdistributor and the outgoing distributor.

The schematic diagram shown in Fig. 7 illustrates the manner in which three multiplex systems may be maintained in synchronous operation and in proper phase relation to repeat signals from any system to any other system in either direction. Three complete multiplex systems U-S, ZS and P-S are represented connecting three different stations U, Z and P respectively to a common or central station S. The transmitting forks at the three outlying stations are indicated at UT, ZT and PT respectively, while the receiving forks are indicated at UR, ZR and PR respectively. The transmitting forks located at the central station S for the three systems are represented at STu, STz, and ST? respectively, while the three receiving forks at station S are represented at SRu, SRz and SR9. The transmitting and receiving distributors which are controlled by the various forks shown in Fig. 7 are represented by the circles which are joined to the respective forks by a single line, and the two lines A and B joining a transmitting distributor with its corresponding receiving distributor represent the two transmission channels.

As shown in Fig. 7, the receiving fork SRu on system U-S drives the transmitting fork ST? on system SP. The fork S'Ip also drives the transmitting fork STz on system SZ. The receiving fork PR at station P drives the transmitting fork PT at the station P, and receiving fork SRp at station S drives the transmitting fork STu at station S on the system U-S. If desired, instead of driving fork STz from fork STp,

this fork may be driven directly from fork SRu by providing an additional contact on fork SRu. It will be understood that the driving connections between the various forks represented schematically by connecting leads in Fig. 7 will include apparatus for adjusting the phase relation between the connected distributors according to the arrangement illustrated in Fig. 6.

If it is desired to transmit from station U through station S'to station P on channel B, it is necessary to secure proper phasing between transmitting distributor TDSp and receiving distributor RDSu. This is accomplished by the phasing connection illustrated in Fig. 6 and diagrammatically represented in Fig. 7 as a simple connection between the two forks controlling these distributors. Also, if it is desired to transmit from station U to station Z through station S on channel A, it will be necessary to secure proper phasing between transmitting distributor TDSZ and receiving'distributor RDSu, and this may be accomplished either by the connection from fork STp as shown in Fig. 7 or by a phasing connection direct from fork SRu to fork STz. With the two connections described above, station U may transmit to station Z or to station P on either channel as desired, or both channels may be used to transmit to one of the distant stations Z or P.

With the arrangement shown in Fig. 7, it is also possible to transmit from station P to station U over either or both channels, as will be understood. In order to permit transmission from station Z to station U or to station P, it will be necessary to make proper phasing adjustments in the connection between fork ZR and fork ZT and inthe connection between fork PR and fork PT in order that proper phasing relation shall exist between transmitting distributor TDSu and the two receiving distributors RDSz and RDSp. The proper phasing relation will be obtained when receiving distributor RDSp is in phase with transmitting distributor TDSp, and when receiving distributor RDSz is in phase with transmitting distributor TDSz. Proper phasing relations are indicated by means of the neon lamps Sla and 31b controlled respectively by switches 32a and 3217. When switch 32a is moved to the left, lamp Ma is connected in circuit with contacts controlled by distributors RDSu and TDSz. With this connection, flashing of the lamp 3| indicates proper phasing between these two distributors as described above in connection with Fig. 6. When switch 32a is moved to the right, lamp ila is connected in a circuit controlled by contacts operated by distributors'I'DSz and RDSz, and by adjusting the phasing connection between forks ZR and ZT, the lamp 31a will indicate the proper phase condition between distributors "I'DSz and RDSz. In a like manner, when switch 32b is moved to the left, lamp 3": is employed to indicate the proper phase relation between distributors RDSu and TDSp, and when switch 32b is moved to the right, lamp Slb is employed to indicate proper phase relation between distributors TDSp and RDSp when the phasing is controlled by the connection between forks PR andPT.

Monitor printers at multiplex station The present invention provides two monitor printers MOPA and MOPB (Fig. 4) at the muldistributor contacts controlling transmitters TA and Th. It will be noted that the added contacts for controlling monitor printer MOPA for channel A are associated with cams B'E to 3'5 which control the contacts of transmitter TB for chan-- nel l3, and the added contacts which control monitor printer MOPB for channel B are associated with cams Ai to A15 which operate the contacts controlling the transmitter TA for channel The plungers for operating the monitor printer contacts are provided with elongated shoes engaging the respective cams in order to prevent overlapping of the printer contacts and to allow for delay in operation of the monitor relay The monitor relay MR which controls the circuit to the monitor printer distributor contacts is energized Toy a connection MRa to the split of the differential meter-on the outgoing line. The monitor relay thereby supplies the monitor printers with signals as they are transmitted over the outgoing line. Contacts 90 and 9d are added to the d'fmtributor for supplying the sixth pulse on the two monitor printer magnets and are associated with cam C6 on opposite sides thereof.

By providing the monitor printers as shown, it is possible for the multiplex operator to make or print a copy of any message which may be relayed through ofiice, or any message which may originate from his office, thus avoiding the necessity oi" using a separate test setfor this purpose. it is also used as'a plant mans check as to whether the repeated signals or the local signals are properly transmitted to the line. With this arrangement it is possible tov dispense with the usual test set provided at the multiplex station.

For the purpose of illustration, our invention has been shown and'de'scribed herein as applied to multiplex systems having only two channels, but it will be understood that the invention may he used in multiplex systems having more than two channels;

Various modifications may be made in the arrangements illustrated without departing from the invention. For example, a single polarized relay may be employed to operate the two movable contacts which, in Fig. 5, arexoperated by separate polarized relays III, II for reversing the polarityof the transmitter contacts, or a single polarized relay may be employed to operate the three movable contacts which, in Fig. 5, are operated by three separate relays W, H and I2.

In accordance with common usage, the term battery is used throughout the specification and accompanying claims to designate any suitable source of direct current.

What is claimed is:

1. In a telegraph repeating system, the combination of an incoming circuit transmitting multiple-unit signal combinations in which the marking impulses are of one polarity for certain units and of opposite polarity for at least one unit in each combination, a normally closed outgoing circuit for operation of a start-stop receiver, means controlled byv the incoming signals for periodically opening said outgoing circuit to transmit a start impulse thereover, means responsive to the receipt of signal impulses of one polarity during the units in which marking impulses are of onepolarity for closing said outgoing circuit, and means responsive to signal impulses of opposite polarity during units in which marking impulses are of opposite polarity for closing'said outgoing circuits 2. In a telegraph repeating system, the comloination of an incoming circuit transmitting multiple-unit signal combinations in which marking impulses are of one polarity for certain units and of opposite polarity for at least one unit in each combination, an outgoing circuit for operation of a start-stop receiver, a synchronous distributor driven in synchronism with the incoming signals, contacts controlled by said distributor for supplying a start impulse to said outgoing circuit, a polarized relay responsive to signals received on said incoming circuit, means including said polarized relay and contacts controlled by said distributor for closing said outgoing oircuit in response to marking impulses oi either polarity.

3. in a telegraph repeating system, the comloination of an incoming circuit transmitting multiple-unit signal combinations in which the marking impulses are of one polarity for. certain units and of opposite polarity for at least one unit of a combination, a synchronous distributor driven in synchronism with signals received on said incoming circuit, an'outgoing' circuit for operating a start-stop receiver, means including contacts on said distributor for supplying a start impulse to said outgoing circuit, a polarized relay connected to said incoming circuit and hav ing a tongue operating between two fixed con tacts, and means controlled by said distributor;

spouse to marking impulses of opposite polarity? i. In a telegraph system, a transmitting station and a receiving station connected by a synchronous telegraph system transmitting fiveunit signal combinations in which marking impulses are of one polarity for the first four units and of opposite polarity for the fifth unit, a synchronous distributor at said receiving station driven in synchronism with signals received over said synchronous system, a telegraph printer at said receiving station controlled by said distributor and operated 'by signals received over said till synchronous system, a distant sub-station provided with a start-stop printer, a start-stop circuit extending from said receiving station to said sub-station for operating said start-stop printer, means including contacts on said distributor for normally closing said start-stop circuit and for interrupting the same prior to receipt of a signal combination, a polarized relay connected to said synchronous system at said receiving station and having a tongue operating between two fixed contacts, a relay for closing said start-stop circuit, a circuit for energizing said relay including one of said fixed contacts and a contact operated to closed position by said distributor during the first four units of a signal combination, and a second circuit for energizing said relay including the second fixed contact on said polarized relay and a contact-operated by closed position by said distributor for the fifth unit of a signal combination.

5. In a telegraph repeating system, the combination of an incoming circuit transmitting fiveunit signal combinations in which the marking ceiving distributor driven in synchronism with signals received on said incoming circuit, an outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five tongue elements normally biased against contacts having one polarity for certain tongues and opposite polarity for at least one tongue, means for driving said transmitting distributor in timed relation with said receiving distributor, means for reversing the polarity on said transmitter contacts, means for normally biasing said polarity reversing means to one position for transmitting spacing impulses to said outgoing circuit, and means responsive to the receipt of marking impulses over said incoming circuit for operating said polarity reversing means from its biased position.

6. In a telegraph repeating system, the combination of an incoming circuit transmitting fiveunit signal combinations in which the marking impulses are of one polarity for the first four units and of opposite polarity for the fifth unit, a receiving distributor driven in synchronism with signals received on said incoming circuit, an outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five tongue elements normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue,

means for driving said transmitting distributor in timed relation with said receiving distributor, and means responsive to the receipt of a marking impulse over said incoming circuit for reversing the polarity of said transmitter contacts.

7. In a telegraph repeating system, the combination of an incoming circuit transmitting five-L unit signal combinations in which the marking impulses are of one polarity for the first four units and of opposite polarity for the fifth unit, a receiving distributor driven in synchronism with signals received on said incoming circuit, an outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five tongue elements normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue, means for driving said transmitting distributor in timed relation with said receiving distributor, a

polarized relay for reversing the polarity on the first four contacts of said "transmitter, a second polarized relay for reversing the polarity of the fifth contact of said transmitter, said polarized relays being provided with means for locking the same in operated position, a circuit for energizing said polarized relays including contacts operated by said transmitting distributor for closing said circuit for a'portion of each signal unit period, a relay for controlling the polarity of current supplied to said energizing circuit, said relay being biased to a position to effect the transmission of spacing impulses over said outgoing circuit, and means responsive to receipt of a marking impulse over said incoming circuit for operating said relay to reverse the polarity of said energizing circuit and thereby operate said polarized relays from normal position to reverse the polarity on the transmitter contacts.

8. In a telegraph repeating system, the combination of an incoming circuit, a receiving distributor driven in synchronism with signals received on said incoming circuit, an outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five tongue ele: ments normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue, means for driving said transmitting distributor in timed relation with said receiving distributor, and means for controlling the polarity of said transmitter contacts in accordance with signal impulses received on said incoming circuit.

9. In a telegraph system, the combination of an incoming circuit comprising a two-channel multiplex system including a receiving distributor operating in synchronism with incoming signals consisting of five-unit combinations in which marking impulses are of one polarity for the first four units and of opposite polarity for the fifth unit, a normally closed outgoing circuit for operating a start-stop receiver, means including contacts on said receiving distributor for opening said start-stop circuit to transmit a start impulse thereover, a second outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five tongue elements normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue, means for driving said transmitting distributor in timed relation with said receiving distributor, means including a relay for reversing the polarity of said transmitter contacts, a second relay for closing said start-stop circuit, a common circuit for energizing said first and second relays, a polarized relay operated by signals received on said incoming circuit and having a tongue operated between two fixed contacts, and contacts controlled by said receiving distributor for preparing said energizing circuit for completion through one of said fixed contacts during the first four signal units, and for preparing said energizing circuit for completion through the other of said fixed contacts for the fifth signal unit.

10. In a telegraph repeating system, the combination of an incoming circuit transmitting fiveunit signal impulses and in which the circuit is normally closed and is opened for the transmission of marking impulses, an outgoing circuit including a tape transmitter and a transmitting distributor for controlling said transmitter, said tape transmitter including five-tongue elements normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue, means for reversing the polarity of the tongue contacts of said transmitter, means including a relay operated by said incoming circuit for normally maintaining said reversing means in a position to transmit spacing impulses over said outgoing circuit and being responsive to receipt of marking impulses over said incoming circuit to reverse the polarity on said transmitter contacts.

11. In a telegraph repeating system, the combination of an incoming circuit including a startfive-unit signal impulses in which the circuit is normally closed and is opened for marking impulses, an outgoing circuit including a tape transmitter and a synchronous distributor for controlling said transmitter, said tape transmitter including five-tongue elements normally biased against contacts having one polarity for the first four tongues and opposite polarity for the fifth tongue, means for reversing the polarity of said transmitter contacts, means including a relay operated by said incoming circuit for normally maintaining said reversing means in a position to transmit spacing impulses over said outgoing circuit and being responsive to receipt of marking impulses over said incoming circuit. to reverse the polarity on said transmitter contacts, and means including contacts operated by said synchronous distributor for transmitting a start impulse to .said start-stop distributor. 1

12. In a telegraph repeating system, the combination oi a start-stop system including a startstop transmitter having five tongues normally biased to spacing position against contacts for impressing battery of the same polarity upon said tongues, a start-stop distributor for successively connecting said tongues to the start-stop line, said distributor having a normally closed stop contact, a start magnet for said start-stop distributor having an energizing circuit including contacts on a control relay, means for imv pressing battery upon the normally closed startstop circuit through the operating winding of said control relay and through the normally closed stop contact on said distributor, means for biasing said control relay to open position against the normal current in said start-stop circuit, a synchronous telegraph system having a transmitting terminal located at the receiving terminal of said start-stop system and including a tape transmitter having five tongue elements normally biased to spacing position against contacts for impressing battery of one polarity on the first four tongues and battery of opposite polarity on the fifth tongue, a synchronous distributor for successively connecting the tongues of said tape transmitter to the outgoing circuit of said synchronous system, means for reversing the polarity of said tape transmitter contacts, a relay for controlling said polarity reversing means and including means for biasing said relay to a position to transmit marking impulses over said outgoing circuit, said relay being energized by said normally closed start-stop circuit and being normally operated to a position for controlling said polarity reversing means to transmit spacings impulses to said outgoing circuit and being responslve to the opening of said start-stop circuit to reverse the polarity on said tape transmitter contacts. a resistance element included in the start-stop circuit at the receiving terminal, and

contacts controlled by said synchronous distributor for short-circuiting said resistance element to thereby increase the current flowing ,in said start-stop circuit and effect the operation of said control relay and to thereby start said startstop distributor. v

13. In a telegraph system, the combination of a start-stop transmitter having five tongue elements normally biased against five spacing contacts and adapted to be operated against five marking contacts, a start-stop distributor having a normally closed stop contact, a start contact and five transmitter contacts connected to the I tongue elements of said start-stop transmitter, a stop transmitter and distributor for transmitting start magnet for said distributor, a two-position switch for controlling the circuits of said transmitter and distributor and including a first contact operable in the first position to connect battery to the transmitter marking contacts and a tacts connected in shunt to the second switch contact, means for biasing said relay to open position, and means for energizing said relay in a circuit including the start-stop line, the stop contact on said distributor and the operating winding on said relay.

for impressing battery of one polarity upon the first four spacing contacts of one transmitter and the fifth spacing contact of the other transmitter, a second pole changing relay for impressing battery oi? opposite polarity upon the fifth spacing contact of the first transmitter and the first four spacing contactsof the second transmitter, means for normally biasing said pole-changing relays to a positionv to transmit spacing impulses over both channels, means for driving said transmitting distributor in timed relation with said receiving distributor, means responsive to signals received on said incoming circuit during one-half cycle of operation of said transmitting distributor for operating said polechanging relays to transmit signals over said outgoing circuit in accordance with signals re- I ceived on the incoming circuit, a second incoming circuit, means responsive to signals received on said second incoming circuit and operable during the second half-cycle of operation of said transmitting distributor for controlling said pole-changing relays to transmit signals over the second channel of said outgoing circuit in accordance with signals received over said second incoming circuit.

- 15. In a telegraph system, the combination of a multi-channel synchronous telegraph system having a receiving terminal in a central Station including at least a pair of telegraph printers and a synchronous distributor for controlling said printers, a second multi-channel synchronous telegraph system having a trans mitting terminal at said central station and including at least a pair of tape transmitters and a synchronous distributor for controlling said transmitters, means for driving said transmitting distributor in timed relation with saidreceiving distributor, an outgoing start-stop circuit connecting said central station with a distant start-stop receiving station, means including contacts controlled by said receiving distributor for transmitting a start impulse over said start-stop circuit, and means including contacts controlled by said receiving distributor for relaying messages received on any channel of said first synchronous system to said outgoing start-stop circuit, means for reversing the polarity of the potential applied to the spacing contacts of said tape transmitters and being normally biased to transmit spacing impulses over the second synchronous system, means including contacts controlled by said receiving distributor for operating said pole-changing means in accordance with signals received on any channel of said first synchronous system to relay signals onto any channel of the .second synchronous system, an incoming start-stop circuit terminating at said central station, and means responsive to signals received on said incoming start-stop circuit for controlling said pole changing means to relay signals over any channel of said second synchronous system in accordance with signals received on said incoming start-stop circuit.

16. In a telegraph repeater system, the combination of a receiving distributor on an incoming circuit, a transmitting distributor on an out going circuit, a motor for driving each distributor, a pair of primary tuning forks of equal speed for controlling the speeds of said motors, a circuit for driving the fork of the transmitting distributor from the fork of the receiving distributor, an auxiliary tuning fork of higher speed than said primary forks, a switch for substituting said auxiliary fork for the primary fork controlling the transmitting distributor, and means responsive to a predetermined phase relation between said distributors for efl'ecting operation of said switch to reconnect the primary fork for controlling said transmitting distributor.

17. In a telegraph repeater system, the combination of a receiving distributor on an incom ing circuit, a transmitting distributor on an outgoing circuit, a motor for driving each distributor, a tuning fork for controlling the speed of the motor driving the receiving distributor, a primary tuning fork associated with the motor of the transmitting distributor and having a speed equal to the speed of the fork controlling the receiving distributor, a circuit for driving the primary fork of the transmitting distributor from the fork of the receiving distributor, an auxiliary tuning fork of higher speed than said primary fork, means including a switch normally biased to position for connecting said auxiliary fork to control the transmitting distributor, a relay for operating said switch to a position to disconnect said auxiliary fork and to connect said primary fork to control the transmitting distributor, and means responsive to a predetermined phase relation between said distributors for energizing said relay.

18. A telegraph repeater system according to claim 17in which a locking circuit is providedfor said relay in' the position connecting the primary fork for controlling the transmitting distributor,

andin which. the phase responsive means controlling said relay comprises a circuit for energizing said relay including in serial circuit relation phasing contacts operated by said transmitting and receiving distributors.

19. In a telegraph system, the combination of a multi-channel multiplex system including a plurality of transmitters, a synchronous distributor for controlling said transmitters to transmit signals over an outgoing line, a plurality of transmitter and a B transmitter, a synchronous distributor for controlling said transmitters to transmit signals over an outgoing line, a monitor printer for channel A connected to said outgoing line and having distributor contacts operated by the cams of said synchronous distributor which operate the B transmitter, and a monitor printer for channel B connected to said outgoing line and having distributor contacts operated by the cams on said synchronous distributor which operate the distributor contacts on the A transv mitter.

21. A combination according to claim 19 in which the plungers for operating the distributor contacts of the monitor printers are provided with elongated shoes engaging the operating cams for preventing overlap of the distributor contacts controlling said printers.

22. A combination according to claim 19 in which. the monitor printers are controlled by means of a polarized relay connected to the split of the diiferential meter on the outgoing line, the tongue of the polarized relay operating between flxed contacts according to the signals transmitted to the line to prepare a circuit for the operation of the selector magnets through the corresponding distributor contacts.

23. A telegraph repeating system according to claim 14 in combination with a monitor printer for channel A on the outgoing circuit and having distributor contacts operated by the cams of the synchronous transmitting distributor which operate the transmitter for channel B, and a second monitor printer for channel B connected to the outgoing circuit and having distributor contacts operated by cams on said synchronous distributor which operate the distributing contacts for the transmitter on the A channel.

24. A combination according to claim 19 in which the monitor printers are controlled by means of a polarized relay connected to the split of the diiferential meter on the outgoing line, the tongue of the polarized relay operating between fixed contacts according to the signals transmitted 'tothe line to prepare a circuit for operation of the selector magnets through the corresponding distributor contacts, and in which the trailing edges of the plunger shoes operating the distributor contacts of the monitor printers are positioned to compensate for lag in operation 01' said polarized relay.

25.1ncqmbination, arotarycam, a pair of switches to'be operated by said cam, a pair of plungers for operating said switches and having shoe elements engaging said cam, said shoe elements having different lengths along the periphery of said cam whereby said switches are operated for different periods of time by said cam.

26. In combination, a movable element having a cam surface, a pair of followers engaging said c'am surface at spaced points thereon, a pair of switches operated by said cam followers, said cam followers having engaging surfaces of different lengths in the direction of movement of said cam whereby for uniform movement of said cam surface, one of said switches is operated for a longer period than the other switch.

27. In telegraphic apparatus, the combination of a switch, a cam for operating said switch from one position to another for the period of one signal unit, a second switch and a cam follower cooperating with said cam for operating said second switch, said cam follower for the second switch having a, longer cam engaging surface than the follower for the first switch whereby said second switch remains operated for only a portion of the period of a signal unit.

28. In a telegraph repeating system, the combination of an incoming circuit, an outgoing circult, a tape transmitter including a transmitting distributor for transmitting over said outgoing circuit multi-imit signal combinations in which marking impulses are of one polarty for certain units and of opposite polarity for at least one unit, Said tape transmitter including a plurality of tongue elements normally biased against contacts having polarities corresponding to the polarities of idle signal combinations on said outgoing circuit, polarized relay means for reversing the I polarity ofsaid transmitter contacts, said polarized relay means being provided with means for locking the same in either operated pofltion. a circuit for energizing said polarized relay means including contacts operated by said transmitting distributor-for closing said circuit for only a portion of each signal unit period, a relay for controlling the polarity of current supplied to said energizing circuit, said relay being biased to a position to effect the transmission of spacing impulses over said outgoing circuit, and means responsive to receipt of a marking impulse over said incoming circuit for operating said relay to reverse the polarity of said energizing circuit and thereby operate said polarized relay means from normal position to reverse the polarity on the transmitter 29. A telegraph repeating system according to r claim 28 in which the transmitting distributor is provided with a pair of alternately operating switches controlled by cams thereon for alternately connecting the distributor contacts for said transmitter to the outgoing line, and in which the distributor contacts for momentarily closing the energizing circuit of the polarized relay means are operated by the same cams which operate said pair of alternating switches for said transmitter,

and in which the engaging surfaces of the cam followers for operating said switches are positioned to compensate for lag in operation of said polarized relay means,

80. In a telegraph repeating system,'the combination'of an incoming circuit, an outgoing circuit, a tape transmitter including a transmitting distributor for transmitting over said outgoing circuit multieunit signal combinations in which marking impulses are of one polarity for certain units and of opposite polarity for at least one unit, said tape transmitter including a plurality of tongue elements normally biased against con-- ,tacts having polarities corresponding to the polarities of idle signal combinations on said outgoing circuit, pole-changing means for reversing the polarity of said transmitter contacts, means for locking said pole-changing means in either operated position, a circuit for energizing said pole-changing means including contacts operated by said transmitting distributor for closing saidlcircuit for only a portion of each signal unit period, means for normally maintaining said polechanging means in a position to eflect transmission of spacing impulses over said outgoing circuit, and means-resp nsive to receipt of a marking impulse over said incoming circuit for completing the jenergizing circuit of said polechanging means through said distributor cone LOUIS HORN JAMES.

DON SPENCER JAMES.

CERTIFIGAI'lii cF CORRECTION. I

LOUIS HORN 1 November 1, .1938. Aims, jar AL.

It is hereby certified that error appears. inthe printed specification of the above numbered patentrequiring correction as follows Page 8 9 s first column, dine 3 8, claim I. for the word "by first occurrence, rread to; and that the: said Letters Patent should be read withthis correction therein that the uncanny conform to the record of the casein; the Patent Office."

Signed and sealed'dmi's 6th dayof December, A. -D. 1958.

(seal) Henry Van Arsdale Commissioner of Patents. 

